This invention relates to an automatic air vent device for a fluid pump of an internal combustion engine and more particularly to an improved arrangement for venting air from a fluid pump without permitting the re-entry of air into the pump through the venting passage.
Many types of fluid pumps are operated on an other than continuous basis. During the times when the pump is not pumping fluid, there is a risk that air will enter the pump and cause difficulties in restarting of the fluid flow once the pump is re-energized. For example, many forms of internal combustion engines employ fluid pumps. As an example, some types of two-cycle, crankcase compression engines have pumps for pressurizing lubricant and delivering it to a lubricating system of the engine. When the engine is not running and the lubricant pump is not being driven, there is a risk that air may enter the pump and cause difficulties in lubricant delivery on restarting. Although venting arrangements have been proposed for venting the lubricant pump so as to purge the air from the system, the venting passages raise the difficulty that air may in fact enter the system through the vent line.
It is, therefore, a principal object of this invention to provide an improved arrangement for venting a fluid pump.
It is a further object of this invention to provide a fluid pump vent that will effectively vent air from the pump but which will prevent the entry of air into the pump when the pump is running.
It is a still further object of this invention to provide an improved venting arrangement for the lubricant pump of an internal combustion engine.